Cylinder lock



INVENTOR 3 Sheets-Sheet l T. H. .JoHNsToNE I CYLINDER LOCK Filed oct.14, 1939 f5 I g /24 Sept. 15, 1942.

Sept. 15, 1942. T. H. JoHNsToNE 2,295,737

CYLINDER LOCK I Filed oct. '14, 1959- s sheets-sheet 2 52 3,4 'Il a 59'l W 45 J5 v www4 IIIIV im 4] IIIH 25 45 I A Il 44' 4; "'55 INVENTCRJ/'f I//n-Zone f BWM@ ATTORNEY Sept 15, 1942 T. H. JoHNsToNE 2,295,737

' CYLINDER Locx s sheets-sheet s Patented Sept. 15, 1942 UNITED STATESPATENT OFFICE CYLINDER LOCK Theodore H. Johnstone, Detroit, Mich.,assigner to The Yale & Towne Manufacturing Company, Stamford, Conn.,acorporation of Connecticut This invention relates to a pick-proof lock,'and more especially to a pick-proof lockof the cylinder type having aseries of key positioned tumblers.

Those skilled in the art fully appreciate that cylinder looks of theclass described, and especial- .ly those having pin tumblers, areusually picked by the application of torque to the key plug of the lock,while the tumblers are'manipulated into release position.

My invention relates to a cylinder lock in which, only after somerotation ofthe key plug, is itvpossible to determine whether or not thetumblers have been properly set.

As a feature of my invention, I utilize a locking element for lockingthe key plug against rotation relatively to the cylinder, the lockingelement being movable to release the key plug for rotation upon properalignment of the tumblers or drivers which are mounted within thecylinder.

As a further feature of my invention, I utilize a locking element whichlocks the key plug against full rotation, while permitting some freerotation thereof, the locking element being mounted for movement torelease the key plug for full rotation in the event the tumblers areproperly aligned by'a key. As still a further feature of the invention,the locking element is held against movement torelease the key pluguntil after some predetermined rotation of the' key plug takes place. Inav pin-v tumbler type of lock, in which drivers andl tumb1ers areemployed, any such rotation of the key plug moves the tumblers out ofalignment with the drivers and makes it impossible to manipulate thetumblers and drivers, all as will be fully appreciated by those skilledin the art.

A feature of value ofl my invention is its speciiic construction. Thusmy lock preferably utilizes a key plug of the usual type, and a cylinderof the usual type, with the feature that the drivers in the cylindercooperate with means for releasing the key plug for rotation. The pintumblers of the key plug are made up of a series of disks lying in eachtumbler bore, so that any key which. will enter the keyvvay of the keyplug will rotate the plug towards release position since the disks willform a parting line at practically any level. I-f `the drivers have beenproperly set by the pin tumblers before rotation, then after somerotation, a locking member will enter, preferably, aligned grooves or-slots formed in the drivers and will permit further rotation of the keyplug. If the locking element cannot enter the driver slots because thedrivers are not prop- `place an armored plate I4.

erly positioned, then the key plug will be blocked againstV furtherrotation. In addition'y it is the initial rotation of the key plugVwhich releases the locking element for movement into the driver slots.The value of these structural features will be readily appreciated bythose skilled in the art.

While I have thus described my invention generally and the relationthereof to the prior art,

it should be appreciated that the basic conception thereof may beembodied in many physical forms. The particular physical forms which myinvention takes in this application are preferred by me, but should notbe construed as limiting the patent monopoly to be granted me.

For a description of two preferred embodiments ofv my invention, I shall`now refer to the drawings wherein Fig. 1 is a vertical section throughacylinder lock of my invention. Fig. 2 is a longitudinal section similarto Fig. 1 but showing the tumblers positioned by a key which is of theproper configuration, that is, a key which is properly -bitted for thelock combination shown.` Fig. 3

is asection taken along lines 3 3 of Fig. 1. Fig. 4 is a section takenalong lines 4 4- of Fig. 1, While Fig. 5 is a View along lines 5-5 ofFig. 1 with the cam removed so that the parts may be better seen. Fig. 6is a View similar to Fig. 4 but showing the parts in release position.Fig. 7 is a perspective View of the entire combination for controllingthe rotation of the key plug and probably best illustrates theinvention. Fig. 8 is a view similar to Fig. l of a modiiication of myinvention. Fig. 9 is a sectional view of Fig. 8 along lines 9 9, whileFigs. l0 and 11 are sections along lines lil-l0 and Il-II respectivelyof Fig.` 8. Fig. 12 is a perspective exploded View of the controllingparts of the modification of Fig. 8.

Referring now more particularly to the drawings, and especially to Figs.1 to '7 inclusive, the lockv of my invention includes a cylinder l0 anda key plug ll. A scalp I-2 is adapted to cover the front I3 of thecylinder lock and to hold in The key plug Il and the cylinder li) eachhave a series of bores, pairs of which are maintained in verticalalignment when the lock is in locked position. In each pair of alignedbores, the key plug bore is designated by reference numeral l5 andcontains a tumbler pin i6 and a series of wafers or disks I1. The uppersurface of the uppermost disk Il lies just below the parting line i8between the key plug and the cylinder. Resting on the upper surface ofthe uppermost disk il and extending into the cylinder bore [5a. is adriver designated by reference numeral I9, and slotted or grooved as at20 for coaction with a release blade 2| best Shown in Fig. '7.

In Fig. 1 it is readily seen that each pair of bores I5, I5a containssiX of the disks I1, a tumbler pin I6 and a driver I9. The parts in eachof the pairs of bores are exactly the same except for the location ofthe slots 20 of the drivers, slots 20 being in varying positions asdetermined by the combination of the lock. It is obvious that in thelock thus far described, the key plug will be rotatable when practicallyany key is inserted, since the disks I1 will form readily severalparting lines corresponding to the parting line I8 between the key plugII and the cylinder I8. Thus, practically any key or tool will act toraise the tumbler pins I6 so that the parting line between certain ofthe disks, or the parting line between the uppermost disk and driver I9,or the parting line between the uppermost disk and the tumblerrpin I 6,will correspond to parting line I8 between the key plug and cylinder.Thereupon, the key plug will be freely rotatable to a predeterminedposition, in which position it will be blocked against further rotation,as will be described presently.

Referring now to Fig. 2, we see the parts of Fig. 1 when a properlybitted key 22 is inserted in the key plug II. It will be noted that thiskey moves the tumbler pins I6 and the various disks I1 to a positionbringing the slots 2D of `the drivers I9 in alignment so that they liein one horizontal plane. Thus, while any key will rotate the key plug II from the position of Figs. l and Sipartially toward a releaseposition, only a properly bitted key such as key 22, will raise thedrivers so that their slots 29 are aligned in the plane of the releaseblade 2|. This release blade 2| is probably best known in Figs. 3 and '7in its relation to the various drivers |9.

At this point7 it will be well toV indicate that the drivers I9 arepressed downwardly in the bores [5a by springs 23 of the usual type, and

Vwhich springs are maintained in position by a plate 24 in a mannerstandard in this art. Moreover, the end of the key plug is formed asillustrated by reference numeral 25 in Figs. 1 and 7 for the mounting ofa usual type of operating cam 25 which is maintained in place by astandard form of spring retainer 21 which fits into Ythe groove 28 ofthe end 25 of the key plug. Of

course, while I have shown a cam 28, any usual type of operatingmechanism may be attached to the key plug Il, as those skilled in theart will fully appreciate.

It will now be well to describe the mounting of the release blade 2 IThis blade may actually be integral with a release plunger 29, bestshown in Fig. '7, but for the sake of economical manufacture, it ispreferably inserted into a slot of the plunger 29, and is held bystaking of one end surface 39 of plunger 29 (Fig. 6) against movementoutwardly of the said slot. At the other end `or the release plunger 29,there is mounted a detent 3| of the shape best shown in Figs. 5 and '7,which detent is secured by riveting of the extension 32 of the plunger29. The cylinder is bored out at 33 for the mounting of the plunger 29for sliding movement. The plunger Vcannot rotate in the bore 33 becauseof the blade 27|, which slides in a groove 34 in the cylinder andextends into the driver bores I5a. As is best seen in Figs. 4 and 6, aportion of the periphery of the plunger 29 is cut away as at 35, andsimilarly a portion of the cylinder adjacent bore 33 is cut away as at36. The cutaway portions 35 and 36 form a cylindrical bore in which ismounted a spring 31 which presses the plunger 29 towards the front endof the cylinder. A plate 38 holds the spring 31 in place, and is securedto the cylinder lock by a screw 39.

The release blade 2| is formed with a series of scallops 49, one ofwhich is adapted to lie in juxtaposed relation to each of the drivers I9when the key plug is in locked position (Fig. 4) It is obvious that whenthe plunger 29 moves into release position (Fig. 6) which it does whenthe drivers are properly aligned, the portions 4I of the blade 2| willenter the aligned slots or grooves 29 of the various drivers I9 underthe influence of the spring 31.

In order to prevent rubbing of the release blade 2| against the driverswhen the key plug is in the locked position of Fig. 4, I utilize theconstruction best illustrated in Fig. '7. There it will be noted thatthe end of the key plug is grooved as at 42, the groove 42 terminatinginan open portion 42a. At each end of the portion 42a., and offset fromgroove 42, is a shoulder or stop 43. Extending from one surface of thegroove 42 is a hump 44 which is midway between stops 43. This hump, inthe locked position of the key plug II (Figs. 4 and 5) cooperates with afoot 45 of the detent 3| to maintain plunger 29 against movement towardthe front of the cylinder lock under the influence of the spring 31. Inthis way, the blade 2| carried by the plunger furnishes no resistance tothe movement of the drivers I9 up and down in their bores |511l by anytype of key, and it is impossible to feel any pressure of the releaseblade 2| against the drivers, thereby obviating any possibility forfeeling the location of the release grooves or slots 20 of the drivers.I shall now describe the operation of my invention.

Let us consider rst the various parts in their initial location of Fig.l. It will be seen that in Fig. 1 the release blade 2| is in theparticular relationship to the drivers I9 which is best illus- Ytratedin Fig. 4. There it will be noted that the spring 31 is pressing theplunger 29 toward the front end of the cylinder tending to bring theparts 4I of the release blade 2| into the slots of the drivers I9. Thescalloped portions 4i) of blade 2| lies in juxtaposed relation to thedrivers I9 but so as not to hinder in any way the upward and downwardmovement of the drivers. This is brought about by the hump 44 of the keyplug II which cooperates with the foot 45 of the detent 3| f-ormaintaining the plunger 29 against the pressure of the spring 31, and inthe position of Fig. 4.

If now a correct key 22 is inserted into the key plug, it will beappreciated that the tumbler pins I6 and the various disks I1 will beraised to bring the drivers |9 into position with their slots 29opposite the release blade 2|. Even with the drivers thus properlypositioned and with the slots 2U aligned with the release blade 2|, itis impossible for the release blade 2| to move to the position of Fig. 6relatively to the drivers I9 because of the hump 44 cooperating with thefoot 45 of the detent 3|. However, rotation of the key plug toward theposition of Fig. 6 will move the hump 44 from opposite foot 45, so thatthe plunger 29 may move under the pressure of spring 31 into the releaseposition of Fig. 6. The plunger 23 Will be limited in its movement bythe presmodified form of my invention.

sure ofthe foot 45 of detent 31| against the innel' surface 46 of thegroove 42. It is apparent, however, that the foot 45 of detent 3| will,when it movee against surface 45, be out of alignment with stops 43, soas to allow a full rotation of the key plug to its release position.

If an improperly bitted key is inserted into the key plug of Fig. 1, itwill be obvious that the key plug will still be capable of some rotationbecause the several parting lines determined by the disks |1 allow suchrotation. The slots 25 of drivers I3 will, however, not be in alignment,as is ap,- preciated, Rotation will bring the parts to the position ofFig. '1, in which it will b e noted that the detent foot 45 will beagainst one of the stops 43, limiting further rotation of the key plugIl. This condition is brought about because when the hump 44 is movedfrom opposite the foot 45 of the detent 3| as by partial rotation of thekey plug the plunger 29 cannot move under the influence of spring 31 tothe position of Fig. 6, because the s lots of the various drivers I9have not been properly aligned relatively to the blade 2|. It isobvious, of course, that in the position of the parts in Fig. '7, it isimpossible to manipulate the pins l5 and the drivers l5, andsurreptitious operation of the lock is therefore effectively blocked.

It is well also to emphasize that in the locked position of the key plugshown in Fig. 7, the

the key plug against the lfoot will net set l up a force against thedrivers i9, since only the spring 31 presses the blade 2| against thedriversV I9, once the key plug has been rotated to bring hump 44 awayfrom the foot 45 of the detent 3|.

Referring now to Figs. 8-12 inclusive, I show a In this modified form,the relation of the drivers, tumblers, and disks is the same as thatindicated in Figs. 1.-'1. Instead of the plunger 29 and the blade 2|, Iuse a plunger 55 having a series of lugs 5| adapted to move into thegrooves 20 of the drivers |9. Also, the plunger is pressed by a spring52 towards the rear of the cylinder instead of toward the front of thecylinder. It is obvious, of course, that when the tumblers are properlyaligned and the drivers I9 are positioned with their slots 20 in theproper plane, the lugs 5| of plunger 5|! will be capable of movementinto the grooves 2,0 of the several drivers. This movement, however,will be against the pressure of spring ,52 rather than under the inuenceof the spring 52.

A control slide 53 is mounted for vertical movement within an opening 54of the cylinder pre,- pared therefor. The slide 53 is bored out at 55for the mounting of a pin 55 which ,is spring pressed relatively toslide 53 by a spring 51 maintained in position by a threaded plug 58secured to the slide 55. The pin 55 has a tapered point bearing againsta cam surface 59 formed on the key plug as best illustrated in 1,2. Thekey plug is grooved as at 65 for cooperation with the under surface ofthe slide 53, and the ends o f the groove 60 form stop surfaces 6| forcooperation with the side walls of the slide 53, all for a purpose to bedescribed presently. The end s urface 62 of the release plunger 5i! Aisformed tapered for cooperation with a complementary tapered surface 63in the end surface of the slide piece 53, and in the locked position ofthe key plug and cylinder illustrated in Fig. 8, surface 52 lies in thecomplementary tapered surface 63. This is true also of the full lineposition of the plunger 50 illustrated in Fig. 10.v It will be well toindicate ati this point that a` threaded plug 64 is secured to v` thecylinder, as best illustrated in Figs. 9 and 10,.- and cooperates with agroove 65 in the plunger 553 lfor retaining the plunger againstrotation, andtherefore, in proper alignment to the drivers I9.--

If, in the modification of Fig. 8, a proper key is inserted and thedrivers aligned so as to bring their slots 2l! opposite the lugs 5I ofthe plunger 50, full release rotation of the key plug is possible in thefollowing manner: The cam surface 59 of the key plug first acts againstthe pin 56 moving the pin upwardly from its position of Fig. 8. Theupward movement of pin 56 will transmit pressure'to the slide 53 throughspring 51. The slide 53 will then move upwardly, camming the plunger 5i)toward the front of the lock and against the pressure of spring 52,provided, however, that movement of the plunger 5i) be at the timepossible through the alignment of the slots 20 of the drivers. It willbe appreciated that if the slots 20 of the drivers I9 have not been putin proper alignment prior to rotation of the key plug, the plunger 5,0will be incapable of movement to carry lugs 5| into the driver grooves.

The slide 53 will then not move upwardly, and

while the spring 51 will be compressed, it will not be effective to movethe plunger 55. It should, of course, be pointed out at this time thatthe spring 51 is in lsuch relation to the spring 52 that a compressionthereof will cause the tapered surface S3 to act against the surface 62of the plunger 50 forcing the plunger against spring 52, when the drivergrooves 29 are properly set. In other words, the spring 51 is a muchmore powerful spring than is spring 52. If the slide piece 53 isincapable of movement upwardly because the plunger 50 is locked by thedrivers against movement, then it is obvious that rotation of key plugwill bring one of the end surfaces 3| against the side of the slide 53,preventing any additional rotation of the key plug `In other words,unless the drivers 25 are properly set, rotation of the key plug willmerely move the pin 55 to compress spring 51while the slide 53 willremain in blocking relation against substantial rotation of the keyplug. I believe the operation of this modification will now be apparent.

I now claim:

1. In a lock of the class described, a cylinder, a key plug rotatablymounted in said cylinder, aligned bores in said cylinder and key plug,tumblers in said bores including a driver having a slot, said key plughaving a keyway into which a key is insertible for positioning thetumblers and means controlled by said driver slot for preventing releaserotaticn of said key plug unless said driver is positioned with its slotin predetermined relation to said means.

2. In a lock of the class described, a cylinder, a key plug rotatablymounted in said cylinder, aligned bores in said cylinder and key plug,tumblers in said bores including a driver having a slot, said key plughaving a keyway into which a key is insertible for positioning saidtumblers. a locking Yelement for preventing rotation of said key plugbeyond a predetermined position, relatively to said cyinder, and meanswhereby a portion of said element moves into the slot of said ,driver torelease said key plug for rotation beyond said predetermined positionwhen said driver is positioned with its slot in predetermined alignmentwith the said portion of said element.

3. In a lock of the class described, a cylinder, a key plug rotatablymounted in said cylinder, aligned bores in said cylinder and' key plug,a driver and a series of disks in said bores, said key plug having akeyway into which a key is insertible for positioning the drivers anddisks in said bores, said drivers and disks being formed to allowrotation of said key plug by a key differing substantially inconguration from the true key of said lock, a control surface on saiddriver, control means for limiting rotation of said key plug in saidcylinder to a limited degree, said control means being movablerelatively to said rcontrol surface of said driver when said driver akey piug rotatably mounted in said cylinder,

aligned bores in said cylinder and key plug, a driver and a series ofdisks in said bores, said key plug having a keyway into which a key isinsertible for positioning the drivers and disks in said bores, saiddrivers and disks being formed to allow rotation of said key plug by akey diiering substantially in configuration from the true key of saidlock, a control surface on said driver, control means for limitingrotation of said key plug in said cylinder to a limited degree, meansfor moving said control means relatively to said control surface of saiddriver upon rotation of said key plug when said driver is properlypositioned prior to any rotation of said key plug, whereby to releasesaid plug for further rotation relatively to said cylinder, and meansfor holding said control means against movement until after rotation ofsaid key plug substantially said limited degree.

5. In a lock of the class described, a cylinder, a key plug rotatablymounted in said cylinder, aligned bores in said cylinder and key plug, adriver and a series of disks in said bores, said key plug having akeyway into which a key is insertible for positio-ning the driver anddisks in said bores, said drivers and disks being formed to allowrotation of said key plug by a key differing substantially inconguration from the true key of said lock, a slot formed in saiddriver, control mechanism including a control piece for limitingrotation ofl said key plug in said cylinder to a particular position,means whereby rotation of said key plug toward said predeterminedposition effects movement of said control piece relatively to saiddriver if said driver has, prior to rotation of said key plug, beenplaced with its slot in proper alignment, said movement of said controlpiece effecting the actuation of said control mechanism to release saidkey plug for further rotation.

6.v In a lock of the class described, a cylinder, a key plug rotatablymounted in said cylinder, aligned bores in said cylinder and key plug, adriver and a series of disks in said bores, said key plug having akeyway into which a key is insertible for positioning the driver anddisks in said bores, said drivers and disks being formed to allowrotation of said key plug by a key differing substantially inconfiguration from the true key of said lock, a slot formed in saiddriver, and a slide piece movable towards said driver and adapted toenter said slot when said driver is properly positioned by a key.

7. In a lock of the class described, a cylinder, a key plug rotatablymounted in said cylinder, aligned bores in said cylinder and key plug, adriver and a series of disks in said bores, said key .plug having akeyway into which a key is insertible for positioning the driver anddisks in said bores, said drivers and disks being formed to allowrotation of said key plug by a key differing substantially inconfiguration from the true key of said lock, a slot for-med in saiddriver, a control piece adapted to enter said driver slot When saiddriver is properly positioned by a key, and means for maintaining saidcontrol piece out of said slot even when said driver is properlypositioned, until said key plug is rotated to carry the bore in said keyplug out of alignment with the bore in said cylinder.

8. In a lock of the class described, a cylinder, a key plug rotatablymounted in said cylinder, aligned bores in said cylinder and key plug, adriver and a series of disks in said bores, said key plug having akeyway into which a key is insertible for positioning the driver anddisks in said bores, said drivers and disks being formed to allowrotation of said key plug by a key differing substantially inconfiguration from the true key of said lock, a sl-ot formed in saiddriver, a control piece movable towards said driver and adapted to entersaid slot when said driver is properly positioned by a key, and meansfor effecting the movement of said control piece into said slot when thekey plug is rotated to carry the bore in said key plug out of alignmentwith the bore in said cylinder.

9. In a lock of the class described, a cylinder, a key plug rotatablymounted in said cylinder, aligned bores in said cylinder and key plug, adriver and a series of disks in said bores, said key plug having akeyway into which a key is insertible for positioning the driver anddisks in said bores, said drivers and disks being formed to allowrotation of said key plug by a key diiering substantially in congurationfrom the true key of said lock, a slot formed in said driver, a controlpiece adapted to enter said slot when said driver is properly positionedby a key, and means for preventing effective rotation of said key pluguntil said control piece enters the slot of said driver.

10. In a lock of the class described, a cylinder, a key plug rotatablymounted in said cylinder, aligned bores in said cylinder and key plug, adriver and a series of disks in said bores, said key plug having akeyway into which a key is insertible for positioning the driver anddisks in said bores, said drivers and disks being formed to allowrotation of said key plug by a key differing substantially inconguration from the true key of said lock, a slot formed in saiddriver, a control piece adapted to enter said slot when said driver isproperly positioned by a key, means for locking said key plug againstrotation beyond a predetermined position releasable upon movement oisaid control piece into the slot of said driver, and means whereby saidcontrol piece is maintained out of said slot until said key plug isrotated to carry the bore in said key plug out of alignment with thebore in said cylinder.

1l. In a lock of the class described, a cylinder, a key plug rotatablymounted in said cylinder, aligned bores in said cylinder and key plug, adriver and a series of disks in said bores, said key Dlug having akeyway into which a key is insertible for positioning the driver anddisks in each of said bores, said drivers and disks being formed toallow rotation of said key plug by a key differing substantially inconguration from thetrue key of said lock, a slot formed in said driver,a control piece adapted to enter said slot when said driver isvproperlypositioned by akey, means for locking said key plug against rotationbeyond a predetermined position releasable upon movement of said controlpiece into the slot of said driver, and means whereby said control pieceis maintained out of said slot until said key plug is rotated.

12. In a lock of the class described, a cylinder, a. key plug r-otatablymounted in said cylinder, aligned bores in said cylinder and key plug, adriver and a series of disks in said bores, said key plug having akeyway into which a key is insertible for positioning the drivers anddisks in said bores, said drivers and disks being formed to allowrotation of said key plug by a key differing substantially inconfiguration from the true key of said lock, a slot formed in saiddriver, a control piece adapted to enter said slot when said driver isproperly positioned by a key, means controlled by said control piece forlocking said key plug against rotation beyond a predetermined positionso long as said control piece is maintained outside the driver slot, andmeans whereby said key plug prevents movement of said control piece intosaid driver slot until said key plug is rotated towards saidpredetermined position, whereby it is impossibie to determine whether ornot the driver has been properly positioned until the key plug bores areout of alignment with the bores in said cylinder.

13. In a lock of the class described, a cylinder,

a key plug rotatably mounted in said cylinder and having a stop surface,aligned bores in said cylinder and key plug, a driver and a series ofdisks in said bores, said key plug having a keyway into which a key isinsertible for positioning the driver and disks in said bores, saiddrivers and disks being formed to allow rotation of said key plug by akey diiiering substantially in conguration from the true key of saidlock, a slot formed in said driver, a control piece adapted to entersaid slot when said driver is properly positioned by a key, a detentcarried by said control piece and cooperable with said-Stop surface onsaid plug to lock said plug against rotation beyond a predeterminedposition so long as said control piece is maintained outside the driverslot, and a surface of said plug preventing movement of said controlpiece into said driver slot until said key plug is rotated towards saidpredetermined position, whereby it is impossible to determine whether ornot the driver has been properly positioned until the key plus' boresare out of alignment with the bores in said cylinder.

14. In a lock of the class described, a cylinder, a key plug rotatablymounted in said cylinder, aligned bores in said cylinder and key plug, adriver and a series of disks in said bores,said key plug having a keywayinto which a key is insertible for positioning the drivers and. disks insaid bores, said drivers and disks being formed to allow rotation ofsaid key plug by a key differing substantially in conguration from thetrue key of said lock, a slot formed in said driver, control mechanismincluding a slide piece for limiting rotation of said key in saidcylinder to a limited degree, and means whereby rotation of said keyplug effects the movement of said slide piece relatively to said driverwhensaid slot is in proper alignment, whereby to `release saidkey plugfrom said control mechanism for further rotation in said cylinder.

l5. In a lock of the class described, a'cylindei", a key plug` rotatablymounted in said cylinder, a seriesof pairsA aligned bores'in saidcylinder and key plug, a driver and a series of disks in'leach of saidpairs of bores, said key plug having a keyway into which' a key isinsertible for positioning the drivers and disks in each of said' pairsof bores, each of said drivers extending into said cylinder when a keyis inserted and said plug rotated, said drivers and disks being. formedto allow rotation of said key plug by a key differing substantially inconguration from the true key of said lock, a slot formed in each ofsaid drivers, control mechanism including a slide piece' for limitingrotation of said'key plug in said cylinder to a particular` position, asurface on said key plug adapted to effect the movement of said slidev`piece relatively to said drivers as said key plug is rotated towardlsaid predetermined position, whereby if said drivers have beenpreviously set withl their slots in proper alignment,` said slide piecewill effect movement of said control mechanism to release saidkey plugfor further rotation, while if said` drivers have not been properly set,said control means will lock said` key plug against said furtherrotation.

16. In a lock of the class described, a cylinder, a key plug rotatablymounted inl said cylinder and having spaced stops, aligned bores in saidcylinder and key plug, key set elements in said aligned bores includinga driver pin lying entirely within the bore in said cylinder when saidkey plug is released for rotation'relatively to said cylinder, saiddriver having a release slot formed therein, a locking element adaptedfor locking saidkey plug against rotation slidably mounted insaidcylinden said locking element being movable to release said key plugwhen said slot in said driver pin is in proper alignment with a' portionof said element.

17. In a lock of the class described, a cylinder, a key plug rotatablymounted in said cylinder and having spaced stops, aligned bores in saidcylinder and key plug, key set elements in said aligned bores includinga driver pin lying entirely within the bore in said cylinder whelisaidkey plug is released for rotation relatively to said cylinder, saiddriver having a release slot formed therein, a locking bar slidable insaid cylinder and positioned relatively to said spaced stops on said keyplug for preventing release rotation of said key plug, and means formoving said locking bar to' release said key plug when said slot in saiddriver pin is in proper alignment with a portion of said locking bar.

18'. In a lock of the class described, a cylinder, a key plug rotatablymounted in said cylinder and `having a keyway, tumblers adapted to bepositioned by a keyv inserted into said keyway, a locking element foreecting the locking of said key plug against free rotation relativelylto said cylinder, said tumblers having slots into which said lockingelement is adapted to enter whereby to release said key plug forrotation, means for moving saidilocking element into said tumbler slots,and meansfor maintaining said locking elementA outv of said tumblerslots until said key plug `is rotated relatively to said cylinder.

19L Ina look of theclassdescribed, a cylinder, a key plug rotatablyvmounted in said cylinder and having a keyway, tumblers adapted to bepositioned by a key inserted into said keyway,` a locking bar forlocking said key plug against free rotation relatively to said cylinderwhile permitting a predetermined degree of rotation, said tumblershaving slots into which said locking bar is adapted to enter whereby torelease said key plug for rotation, a spring pressing said locking bartowards said tumbler slots, and means for maintaining said locking barout of said tumbler slots until said key plug has been rotatedrelatively to said cylinder as permitted by said locking bar.

20. In a lock of the class described, a cylinder, a key plug rotatablymounted in said cylinder and having a keyway, spaced stops formed onsaid key plug, tumblers adapted to be positioned by a key inserted intosaid keyway, a locking bar carried by said cylinder and cooperable withsaid spaced stops on said key plug for locking said key plug againstfree rotation relatively to said cylinder while allowing limitedrotation of said key plug as determined by the distances between saidstops, said tumblers having slots into which said locking bar is adaptedto enter and to move out of the plane of said stops whereby to releasesaid key plug for rotation, and means maintaining said locking bar outof said tumbler slots until said key plug has been rotated relatively tosaid cylinder.

2l. In a lock of the class described, a cylinder, a key plug rotatablymounted in said cylinder and having a keyway, spaced stops formed onsaid key plug, tumblers adapted to be positioned by a key inserted intosaid keyway, a locking bar carried by said cylinder and cooperable withsaid spaced stops on said key plug for locking said 4key plug againstfree rotation relatively to said cylinder while allowing limitedrotation of said key plug as determined by the distances between saidstops,rsaid tumblers having slots into which said locking bar is adaptedto enter whereby to release said key plug for rotation, a springpressing said locking bar into said tumbler slots and out of the planeof said spaced stops, and means for maintaining said locking bar out ofsaid tumbler slots until said key plug has been rotated relatively tosaid cylinder.

22. In a lock of the class described, a cylinder, a key plug rotatablein said cylinder and having a keyway through which key set tumblers areoperated by a key in said keyway, a locking bar slidably mountedrelatively to and between said cylinder and key plug for slidingmovement parallel to the axis of rotation of said, key plug in saidcylinder, means whereby in one position said bar interlocks said keyplug and said cylinder to prevent full rotation of said key plug,

while allowing limited rotation of said key plug relativelyr to saidcylinder, key set tumblers having slots into which portions of said barenter when said tumblers are properly aligned, a spring urging said bartowards said tumbler slots and out of said interlocking position, andmeans whereby said bar is maintained in interlocking position` againstthe pressure of said spring until Vsaid key plug is rotated the limitedamount permitted by said bar.

23. In a lock of the class described, a cylinder, `a key plug rotatablymounted in said cylinder, aligned bores in said cylinder and key plug,tumblers in said bores including a driver having a slot, said key plughaving a keyway into which a key is insertible for positioning saidtumblers, a locking element for preventing rotation of said key plugbeyond a predetermined position relatively to said cylinder, meanswhereby a portion of said element moves into the slot of said driver torelease said key plug for rotation beyond said predetermined positionwhen said driver is positioned with its slot in predetermined alignmentwith the said portion of said element, and means for maintaining saidelement against movement into said driver slot until said key plug isrotated towards said predetermined position.

24. In a lock of the class described, a cylinder, a key plug rotatablymounted in said cylinder, a series of pairs of aligned bores in saidcylinder and key plug, a driver and a series of disks in each of saidpairs of bores, said key plug having a keyway into which a key isinsertible for positioning the drivers and disks in each of said pairsof bores, each of said drivers extending into said cylinder when a keyis inserted and said plug rotated, said disks being formed to allowrotation oli' said key plug by any key of substantially predeterminedconfiguration, a slot formed in each of said drivers, a slide piecemounted for sliding movement in said cylinder and held against rotarymovement, spaced stops formed on said key plug and adapted to impingeagainst surfaces of said slide piece as said key plug is rotated wherebyto limit rotation of said key plug, a spring pressing against said slidepiece to move said surfaces out of the plane of said stops to releasesaid key plug for free rotation, said drivers preventing such movementof said slide piece except when positioned by a proper key with theirslots in predetermined alignment, and means whereby said key plug holdssaid slide piece against said movement even when said drivers are inproper alignment, until predetermined rotation of said key plug.

25. In a lock of the class described, a cylinder, a key plug rotatablein said cylinder, key set elements for controlling the rotation of saidkey plug in said cylinder adapted for positioning by a key, said key setelements being so constructed that said key plug is rotatable from alocked toward a release position even when said key set elements areimproperly set by a key, a locking element for limiting said rotation toa predetermined position, and movable into position to release said keyplug for full rotation when said key set elements are properly set by akey and said key plug rotated, and means for holding said lockingelement against movement until after some rotation is imparted to saidkey plug.

26. In a lock of the class described, a cylinder, a key plug rotatablymounted in said cylinder and having a keyway, tumblers adapted to bepositioned by a key inserted into said keyway, a locking element foreffecting the locking of said key plug against free rotation relativelyto said cylinder, said tumblers having slots into which said lockingelement is adapted to enter whereby to release said key plug forrotation, a spring for resisting the movement of said locking elementinto said tumbler slots, and spring means through which rotation of saidkey plug eiects the movement of said locking element into said tumblerslots.

key set elements by the true key releases said control means formovement to release the key plug for further rotation, and spring meansthrough which rotation of said key plug said predetermined degreeeffects the movement of said control means to release the key plug forsaid further rotation.

28. In a lock of the class described, a cylinder, a key plug rotatablein said cylinder, key set elements in said cylinder and key plug adaptedfor positioningr by a key, said key set elements being so constructedthat said key plug is rotatable from a locked toward a release positioneven when said key set elements are improperly set by a key, controlmeans controlled by the key setting of said elements for limitingrotation of said key plug in said cylinder to a predetermined degree,means whereby the proper setting of said key set elements by the truekey releases said control means for movement to release the key plug forfurther rotation, a spring for resisting said movement of said controlmeans when said key set elements are set by a true key, and spring meansthrough which rotation of said key plug said predetermined degreeeffects the movement of said control means to release the key plug forsaid further rotation.

29. In a lock of the class described, a cylinder, a key plug rotatablymounted in said cylinder, aligned bores in said cylinder and key plug,turnblers in said bores including a driver having a slot, said key plughaving a keyway into which a key is insertible for positioning saidtumblers, a locking element for preventing rotation of said key plugbeyond a predetermined position relatively to said cylinder, and meanswhereby rotation of said key plug toward said predetermined positioneffects the movement of a portion of said locking element towards saiddriver slot.

THEODO-RE H. JOHNSTONE.

